Device for monitoring the operation of a dosage dispenser of a liquid additive in a main liquid, and dosage dispenser provided with such a device

A device (1) for monitoring the operation of a dosage dispenser (2) which includes a suction pipe (5) suitable for being plunged into the liquid additive (3) contained in a container (6), the monitoring device including elements for detecting the suction of liquid additive and elements for displaying operating parameters of the dosage dispenser; the detection elements include a tube (10), separate from the suction pipe (5), one end (10b) of which is configured to be plunged into the container of liquid additive, and the other end (10c) is kept stationary relative to the suction pipe in order to be located outside the container, the other end (10c) being closed and provided with a sensor of the air pressure inside the tube, the sensor outputting an electrical signal, and elements for using the signal from the sensor, connected to the outlet of the sensor, to provide information on the operation.